Technical Field
The present invention relates to a recording tape cartridge that rotatably accommodates a single reel on which a recording tape such as a magnetic tape or the like is wound, and to a method of molding a release member provided in the recording tape cartridge.
Related Art
A recording tape cartridge that has been known heretofore rotatably accommodates a single reel, on which a recording tape such as a magnetic tape or the like is wound, inside a case. This recording tape cartridge enables a reduction in accommodation space during storage and may record large volumes of data. The recording tape cartridge is equipped with a locking member, which is for locking the reel so as not to rotate inside the case at times of non-use, and with a release member, which is for releasing the locking of the locking member at times of use.
During use of the recording tape cartridge, that is, during rotation of the reel, a spherical surface-shaped protrusion portion of the locking member and a flat surface-shaped touching surface of the release member, which are both resin members, slidingly contact one another. Accordingly, in the light of increasing rotation speeds aimed at shortening access times to desired recording positions and data, a recording tape cartridge has been proposed heretofore (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2004-348839) in which a metallic plate that structures the touching surface is provided at a main body of the release member by caulking.
However, with the structure in which a metallic plate is caulked to the main body of the release member, a number of steps in fabrication of the release member increases, and a response to an increase in costs is required. Accordingly, providing the metallic plate at the main body of the release member by insert-molding has been considered. However, in this case there is a risk of the touching surface of the metallic plate being damaged by a die.
If the touching surface of the metallic plate is damaged, there is concern that behavior of the release member relative to the protrusion portion of the locking member may be disordered during rotation of the reel. If the behavior of the release member during the rotation of the reel is disordered, there is concern that the protrusion portion of the locking member may receive, for example, diametric direction force components from the touching surface of the release member, and that consequently noise will be generated during rotation of the reel.